4.1/3.5 kV breakdown voltage in depletion/enhancement-mode MOCVD-grown Ga 2 O 3 MOSFETs on sapphire substrates

Abstract In this work, we realized high-performance β -Ga 2 O 3 power MOSFETs grown via metal-organic chemical vapor deposition on sapphire substrates. High-resolution X-ray diffraction and HRTEM characterization confirmed single crystallinity of the β -Ga 2 O 3 heteroepitaxial film on c -plane sapphire. Low-damage Si⁺ ion implantation followed by annealing was conducted to enhance conductivity. Utilizing a recessed channel architecture, we fabricated both D-mode and E-mode β -Ga 2 O 3 MOSFETs. The inclusion of source and gate field plates, and thick gate trench dielectric yielded the breakdown voltage ( V br ) of 4129 V and 3509 V for D-mode and E-mode devices respectively. Both device types demonstrate breakdown characteristics comparable to homoepitaxial β -Ga 2 O 3 MOSFETs, while surpassing previously reported heteroepitaxial counterparts on sapphire substrates.